Professional type snorkels for use with scuba diving equipment or snorkeling are generally of a very basic design comprising a breathing tube which is attached to a rubber or silicone mouthpiece assembly. The purpose of a snorkel is to permit the user (hereinafter referred to as diver) to keep his face, including his eyes, mouth and nose, under the surface of the water while allowing him to continue breathing through the snorkel apparatus. The diver places one end of the snorkel breathing apparatus in his mouth and positions the snorkel so that the breathing tube extends around the side of his head and protrudes above the surface of the water.
Unfortunately, snorkel apparatus continuously fill with water, either partially or completely, due to a variety of occurrences. First, during normal surface swimming, the upper end of the breathing tube extends only a few inches above the surface of the water. Splashing at the surface of the water, either due to waves or the swimming motions of the diver himself, causes water to lap over the open end of the breathing tube and fall into the snorkel. Water may also enter the snorkel when the diver turns his head to the side causing the open end of the snorkel to either partially or completely submerge for an instant. Water also flows into the breathing passage of the snorkel due to leakage around the seal between the diver's mouth and the mouthpiece. Another way in which water enters into the breathing passage of the snorkel is when the diver deliberately submerges his entire head including the snorkel in order to swim downward into the water. When the diver resurfaces the entire snorkel breathing passage will be completely filled with water.
When the snorkel becomes either partially or completely filled with water, the diver must clear out the water in order to resume normal breathing. Typically, the quickest and easiest way to clear the breathing passage is to strongly and quickly exhale a burst of air through the snorkel so as to force the water out of the upper opening. The first burst of air will usually clear out enough water so that the diver can breathe through the snorkel. However, some water will usually remain in the snorkel making breathing difficult for the diver. Typically, the diver must force two or three bursts of air through the breathing passage before all the water is cleared. Alternatively, many divers cannot produce the force necessary to completely clear the snorkel of water and therefore must lift their heads completely above the water and remove the snorkel to drain it. This operation is extremely time consuming, tiring and cumbersome since the diver must tread water in order to keep his head above water during the operation. In addition, it is frequently undesireable for the diver to lift his head out of the water because this would cause the diver to lose sight of something he is observing beneath the water.
In order to reduce the problems of clearing the snorkel or breathing passage of water, some snorkels are provided with a single purge valve placed in various positions to evacuate water. Typically, the purge valve is placed at the end of a separate chamber from the main breathing passageway, somewhere on the apparatus so that it will remain underwater during normal snorkeling. The separate chamber is connected to the main chamber at the end opposite the purge valve.
When the diver resurfaces after completely submerging his head, the breathing passage is completely filled with water. The water in the breathing tube will automatically drain through the purge valve until the water level in the tube is equal to the surface of the water. Although this decreases the amount of water which the diver must clear from the tube, the diver must still clear the breathing passage through the upper opening of the tube with a blast of air from his lungs. With these types of snorkels, when the diver exhales into the tube, some water will evacuate through the purge valve and some water will evacuate through the upper opening. A fairly strong burst of air is still required.
It is an object of the present invention to provide an improved snorkel.
It is another object of the present invention to provide a snorkel with improved means for purging the breathing chamber of water.
It is a further object of the invention to provide an improved snorkel wherein up to 100% of the water in the breathing passage is evacuated through purge valves adjacent to the diver's mouth, thereby reducing the force needed to clear the snorkel of water.